Risk factors, complications and outcome in anaesthesia. A pilot study.

In a screening study the strength of association between individual risk factors and post-operative outcome was examined using three-dimensional variate analyses. In a study of 1016 patients, the incidence of life-threatening complications during anaesthesia was low (0.2%), whereas minor complications were seen in about 6% of the patients. Opiate overdose or residual curarization occurred in almost 2% of the cases. One hundred and eleven variables were prospectively assessed and 35 pre-operative variables were evaluated for their possible relationship to one event: post-operative mechanical ventilation (MV). The statistical method suggested that seven of the pre-operative variables seemed to be associated with post-operative MV. Eleven out of 20 patients with respiratory failure who were treated with MV died after anaesthesia (55%) compared with the overall hospital mortality of 2.7%.